M.M.
My theory is that you either get night time sleepers, or nappers. But not both.
Neither of my kids nap well. DD is 7mos old and it's a battle with her every day.
I have had to pay very close attention to her sleep signals, and beat it to the punch. 9 weeks is hard to guage, since she's just developing those habits now. Start watching for how long she's up between being tired during the day. (At that age, I got about 2 hrs out of each kid). Then start rocking - or whatever - about 15 minutes early.
Now, I get about 3 hrs between naps for the baby. So at the 2.5hr mark, I take her upstairs and start rocking. If I can get her BEFORE she starts rubbing her eyes and pulling on her ears, then she'll conk right out.
It's taken me about 6 mos to get that!
Good luck. I feel your pain! There are plenty of days where she'll close her eyes, and as soon as I move her to the crib, they pop wide open and she smiles as me. It's maddening!